PGP and cancer: More importantly, the notable MDR reversal effects of BI-2865 has been further confirmed in KBv200 xenograft cancer model, and the vivo results also indicated a well-tolerance of BI-2865 and Paclitaxel co-administration (Fig. 2), suggesting low doses of BI-2865 could markedly sensitize P-gp mediated MDR tumors to chemo-drugs, and enhanced the therapeutic effect both in vitro and in vivo.